Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.

Life habit: lichenized Thallus: crustose, areolate, without elongated lobes; prothallus: absent surface: blue-gray, verruculose, sorediate soredia: fine, in delimited, laminal, cupuliform soralia cortex: cellular, 14-21 µm thick, granules absent; medulla without granules Apothecia: adnate or stipitate, 0.2-1 mm in diam., lecanorine disc: brownish orange or orange, flat or slightly concave, epruinose margin: persistent, flush or slightly raised; thalline margin present, concolorous with thallus; proper margin not visible parathecium: elongate to oval cells; exciple below hypothecium amorphous epihymenium: golden, K+ red hymenium: hyaline, 60-75 µm tall paraphyses: 1-2 tip cells slightly swollen, with few branches; subhymenium hyaline asci: cylindrical, 8-spored ascospores: hyaline, 2 locules, ellipsoid, 11-14(-15.5) x 5.5-7 µm, isthmus 2-4 µm, spore end wall thin Pycnidia: present, totally immersed, ostiole black Spot tests: apothecial margin K+ violet, 10% N+ violet, cN+ violet, C+ violet; thallus K+ violet, 10%N+ violet, cN+ violet unidentified anthraquinones and thalloidima green. Substrate and ecology: on bark World distribution: North America Sonoran distribution: Arizona and Baja California. Notes: Caloplaca pinicola has a dark gray thallus and apothecial margins and is very similar to C. cerina that has a continuous thallus while C. pinicola has a thicker areolate thallus sometimes with blue gray soredia and the spore isthmus is narrower. The soredia are variable and sometimes rare or absent. The prominent dark gray thalline margin of the apothecia of C. pinicola separates it from C. ahtii that also has blue gray soredia. Caloplaca pinicola is probably more common but has not been separated from C. cerina.